ABSTRACT
BACKGROUND: The presence of oligoclonal IgM bands (OCMB) in cerebrospinal fluid (CSF) is an unfavourable prognostic marker in multiple sclerosis. There is no commercial test to investigate OCMB status. However, a sensitive and specific isoelectrofocusing (IEF) and western blot method was described. We aimed to study the inter-centre reproducibility of this technique, a necessary condition for a reliable test to be incorporated into clinical practice. METHODS: The presence of OCMB was analysed by IEF and western blot with prior reduction of pentameric IgM. We assayed the reproducibility of this test in a blinded multicentre study performed in 13 university hospitals. Paired-CSF and serum samples from 52 neurological patients were assayed at every centre. RESULTS: Global analysis rendered a concordance of 89.8% with a kappa value of 0.71. CONCLUSION: These data indicate that OCMB detection by means of IEF and western blot with IgM reduction shows a good interlaboratory reproducibility and thus can be used in daily clinical setting.
Subject(s)
Immunoglobulin M/cerebrospinal fluid , Blotting, Western , Humans , Limit of Detection , Reproducibility of Results , SpainABSTRACT
We prospectively assessed the risk of second relapse in 192 patients with clinically isolated syndromes (CIS) divided into three groups: patients lacking oligoclonal IgG bands (OC-IgG, 25.7%), those showing OC-IgG (52.4%), and those with both OC-IgG and lipid-specific IgM bands (LS-OC-IgM, 22%). OC-IgG increased 9.3-fold the risk compared to lacking OC-IgG; OC-IgG+LS-OC-IgM increased the risk 39.6-fold compared to not having OC-IgG and 4.4-fold compared to having only OC-IgG. Median time to second relapse was 0.7 years for patients with OC-IgG+LS-OC-IgM and 3.3 years for those with only OC-IgG. Therefore, CSF analysis identifies CIS patients at risk of second relapse.
Subject(s)
Demyelinating Diseases/immunology , Demyelinating Diseases/metabolism , Oligoclonal Bands/blood , Oligoclonal Bands/cerebrospinal fluid , Adult , Analysis of Variance , Demyelinating Diseases/mortality , Demyelinating Diseases/pathology , Female , Humans , Immunoglobulin G/blood , Immunoglobulin G/cerebrospinal fluid , Immunoglobulin M/blood , Immunoglobulin M/cerebrospinal fluid , Kaplan-Meier Estimate , Longitudinal Studies , Magnetic Resonance Imaging/methods , Male , Recurrence , Risk Factors , Young AdultABSTRACT
The objective of this study was to investigate whether the presence of lipid-specific oligoclonal IgM bands (LS-OCMB) in cerebrospinal fluid (CSF) influences the response to treatment with beta-interferon in relapsing-remitting multiple sclerosis (RRMS) patients. We performed a collaborative prospective study including RRMS patients with brain MRI and LS-OCMB studies performed before starting interferon treatment. The primary endpoint was the risk of having a relapse after treatment initiation. Secondary endpoints included relapse rate, relapse-rate reduction, proportion of relapse-free patients and proportion of patients with sustained disability increase during follow-up. One-hundred and two patients were included. After a mean follow-up of 37.4 months, the risk of suffering a relapse was two-fold higher in patients with LS-OCMB (hazard ratio 2.0, 95% confidence interval 1.1-3.8). LS-OCMB+ patients showed lower reduction in relapse rate (51.8% versus 80.8%; p < 0.0001), higher relapse rate in the first year (0.8 versus 0.2; p = 0.001), lower proportion of relapse-free patients (25% versus 61.3%; p = 0.003), and higher proportion of patients with sustained 1.0 increase in the Expanded Disability Status Score (45% versus 12.9%; p = 0.0003). In conclusion, LS-OCMB can have an influence on the response to interferon treatment in RRMS patients. They could be used as a biological marker to predict high inflammatory activity after treatment.
